warner



J. s. WARNER. Sewing Machine Tension-Wheel.

,122. Patented Jan. 25, 18.70.

gttum NPETERS. FNpTO-LITHOGRAPHER. WASHINGTON. D C- ttnitrd gtatrz @atwt (Militia.

Letters Patent No. 99,122, dated January 25, 1870 THREAD-TENSION DEVICE FOR SEWING-MACHINE.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that I, J. S. WARNER, of Ogdensburg, in the county of St. Lawrence, and State of New York, have invented a new and improved Tension Vheel for Sewing-lilachines; and I do hereby declare thatthe following is a-full, clear, and exact description thereof, which will enable others skilledin theart to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to improvements in the construction of tension-wheels for sewing-machines; and consists in making them of two disks of metal, hav-' ing hubs or projections and small grooves on one side, the latter being near the periphery, and another disk of thin metal, having radialslits extending from the periphery to a circle of about the same diameter as the hubs of the other disks, and the parts between these slots curved alternately in opposite directions, all clamped together by screws, or otherwise, with the thin slit-ted disk between the hubsof the other two, and the edges of the projecting parts fitting the grooves in the sides of the other disks.

The object of this improved construction is to provide and maintain such acute angles at the bottom of the grooves in which the thread is wound, that no matter how fine the thread may be, it will so wedge into the grooveas to prevent slipping, which occurs more or less on all other tension-wheels now in use, sometimes requiring it to be wound two or more times around the wheel, which is objectionable, because of the rubbing of one part on the other, due to the one winding on the other, and the obstructions to winding off properly, caused thereby.

Figure 1 is a side elevation of my improved tensionwheel;

Figure 2 is a side elevation of one of the clampingdisks; and

Figure 3 is a section on the line a: a: of fig. 1.

Similar letters of reference indicate corresponding parts.

A A are two disks, of metal, with one plane side, and with a hub, B, and groove, 0, on the otherside.

D is a thin disk, slightly less in diameter than the others, and provided with numerous radial slits, either cut or sawed, from the periphery to the dotted circle shown in fig. 2, which is of about the same diameter as the hubs B.

The parts F between these slits are curved outward alternately each way, to form a groove for winding the thread in;.and the disk D is arranged between the disks A and B, so that all may be clamped together by screws G, or other means, as clearly shown in fig. 3.

Then so clamped together, the outer edges of the parts 1" fit into the grooves G of the disks A, where by they are protected against being bentoutward too far, by which the acute angle requiredfor the bottom of the groove would be destroyed. The thread is thereby also prevented from catching on'the ends of the projections, or passing behind them.

This mode of construction provides a more acute angle at the bottom of the groove than can be made in any other way, and thereby any thread, no matter how fine, will wedge into it, so as to produce the necessary tension by-windin g itonce around the wheel.

Having thus described my invention,

1 claim as-ncw, and desire to secure by Letters Patent The combination, with the notched disk D, of the adjustable disks A and B, when all are constructed and arranged to operate as and for the purpose set forth.

The above specification of my invention signed by me, this 27th day of November, 1869.

\Vitnesses: J. S. \VARNER.

GEO. W. MABnn, ALEX. F. ROBERTS. 

